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    <title>Transport Research International Documentation (TRID)</title>
    <link>https://trid.trb.org/</link>
    <atom:link href="https://trid.trb.org/Record/RSS?s=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" rel="self" type="application/rss+xml" />
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    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
    <docs>http://blogs.law.harvard.edu/tech/rss</docs>
    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
    <image>
      <title>Transport Research International Documentation (TRID)</title>
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      <link>https://trid.trb.org/</link>
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    <item>
      <title>A wind-driven device can improve the cooling efficiency of clogged crushed-rock embankments in permafrost regions</title>
      <link>https://trid.trb.org/View/2643938</link>
      <description><![CDATA[To improve the poor cooling efficiency of crushed-rock embankments (CREs) clogged by snow or sand, a novel fully automatic wind-driven air pumping device is developed to enhance convective heat transfer. Numerical simulations demonstrate that this device can increase the internal airflow by several orders of magnitude, thereby significantly strengthening forced convection and improving the overall cooling performance. The embankment and underlying permafrost experience notable temperature reductions, with the cooling effect gradually diminishing with depth. Even for deep permafrost layers, the device still exhibits a remarkable cooling effect. Among the tested configurations, the U-shaped crushed-rock layer embankment equipped with the wind-driven device exhibits the most pronounced cooling performance, outperforming the crushed-rock interlayer embankment with the device due to its higher overall convective efficiency from the revetment crushed-rock layers. Both equipped CREs effectively enhance the ground heat release capacity and substantially mitigate long-term settlement deformation, demonstrating a significant improvement in the thermal stability and structural safety of embankments. Furthermore, the proposed device shows strong adaptability to snow accumulation and sand clogging, ensuring reliable operation under severe environmental conditions. This study provides an innovative and practical approach for improving the cooling performance of CREs in snowy and sandy permafrost regions.]]></description>
      <pubDate>Thu, 26 Feb 2026 09:21:08 GMT</pubDate>
      <guid>https://trid.trb.org/View/2643938</guid>
    </item>
    <item>
      <title>Ice Particle Analysis of the Honeywell ALF502 Engine Booster</title>
      <link>https://trid.trb.org/View/1832886</link>
      <description><![CDATA[A flow and ice particle trajectory analysis was performed for the booster of the Honeywell ALF502 engine. The analysis focused on two closely related conditions one of which produced an icing event and another which did not during testing of the ALF502 engine in the Propulsion Systems Lab (PSL) at NASA Glenn Research Center. The flow analysis was generated using the NASA Glenn GlennHT flow solver and the particle analysis was generated using the NASA Glenn LEWICE3D v3.63 ice accretion software. The inflow conditions for the two conditions were similar with the main differences being that the condition that produced the icing event was 6.8 K colder than the non-icing event case and the inflow ice water content (IWC) for the non-icing event case was 50% less than for the icing event case. The particle analysis, which considered sublimation, evaporation and phase change, was generated for a 5 micron ice particle with a sticky impact model and for a 24 micron median volume diameter (MVD), 7 bin ice particle distribution with a supercooled large droplet (SLD) splash model used to simulate ice particle breakup. The particle analysis did not consider the effect of the runback and re-impingement of water resulting from the heated spinner and anti-icing system. The results from the analysis showed that the amount of impingement for the components were similar for the same particle size and impact model for the icing and non-icing event conditions. This was attributed to the similar aerodynamic conditions in the booster for the two cases. The particle temperature and melt fraction were higher at the same location and particle size for the non-icing event than for the icing event case due to the higher incoming inflow temperature for the non-event case. The 5 micron ice particle case produced higher impact temperatures and higher melt fractions on the components downstream of the fan than the 24 micron MVD case because the average particle size generated by the particle breakup was larger than 5 microns which yielded less warming and melting. The analysis also showed that the melt fraction and wet bulb temperature icing criterion developed during tests in the Research Altitude Test Facility (RATFac) at the National Research Council (NRC) of Canada were useful in predicting icing events in the ALF502 engine. The development of an ice particle impact model which includes the effects of particle breakup, phase change, and surface state is necessary to further improve the prediction of ice particle transport with phase change through turbomachinery.]]></description>
      <pubDate>Fri, 18 Mar 2022 12:17:11 GMT</pubDate>
      <guid>https://trid.trb.org/View/1832886</guid>
    </item>
    <item>
      <title>Gradient-like minimization methods for aeroengines diagnosis and control</title>
      <link>https://trid.trb.org/View/1843196</link>
      <description><![CDATA[Nowadays, there is an ever growing interest for gas turbine and aeroengines prognostics. The capability to assess not only the current state of an asset, but also to be able to predict its remaining useful life (RUL), and hence to perform condition-based maintenance (CBM) —if, and only when, it is needed— can represent a huge deal in the manufacturer profits. Against the plethora of data-driven methods that have arisen in the past few years, there is still some knowledge to be gained in terms of understanding the underlying phenomenology of engine degradation. In fact, it is certainly a non-trivial problem, to realize what has happened to the rotating components of an engine just by observing the pressure being measured by certain sensor rise, or some other temperature measured along the main gas-path decrease its value. In this regard, model-based approaches —and, in particular, gas path analysis (GPA)— can assist us in gaining such knowledge. In this paper, a non-linear GPA technique is revisited, introducing some novelties to the solver, and making use of current computational methods and resources, to establish a solid ‘foundation’ that will serve as the basis for further research.]]></description>
      <pubDate>Thu, 23 Sep 2021 08:36:24 GMT</pubDate>
      <guid>https://trid.trb.org/View/1843196</guid>
    </item>
    <item>
      <title>Research on probabilistic risk assessment of aeroengine rotor failure</title>
      <link>https://trid.trb.org/View/1757996</link>
      <description><![CDATA[The failure of aeroengine rotor will cause a great threat to the flight safety. A new risk assessment model to assess the possibility and severity of failure of aeroengine rotor is presented addressing the problems that its failure samples are not sufficient and that early potential failures are not easy to recognize. The key point of this model is to determine the risk mechanism with diverse failures, failure phase, failure process, historical failure time, and check interval. The risk mechanism is to determine the failure is in the state of relevant failure or not. The failure phases are divided from initial operational state to potential failure and eventually developed to functional failure. The failure process is to confirm possible cascading failure of parts at the same level or of systems. Historical failure time is useful to describe the tendency of failure in the future by Weibull distribution, which is very suitable to depict the rule of mechanical parts failure. Considering check intervals makes the model more complete. These factors to be considered in risk modeling are complete. The relationship has been simulated between failure process and check interval of engine rotor. The risk assessment flowchart of engine rotor has been established after determining failure correlation including nonrelevant failure and relevant failure to another part. The primary failure probability has been predicted through Monte Carlo simulation. In the case of aircraft bursting into flames due to fuel tank breakdown resulted from turbine disk debris, the probability and process model of relevant turbine debris failure have been established through the cartridge receiver, airfoil, fuel tank in sequence. The relevant failure risk of engine part has been evaluated to ensure the safe operation of aeroengine. The aeroengine rotor failure risk model will have great significance in eliminating potential failure and reducing sudden failure.]]></description>
      <pubDate>Fri, 25 Jun 2021 18:38:53 GMT</pubDate>
      <guid>https://trid.trb.org/View/1757996</guid>
    </item>
    <item>
      <title>Wireless-based technology for optimizing of operation of the aviation engine control system</title>
      <link>https://trid.trb.org/View/1849509</link>
      <description><![CDATA[An approach for improving of efficiency the operation of distributed control system of aviation engine based on wireless technology with high productivity and resolution of wave distributed surface has been presented. It can be applied for development of new principles of correct location the nodes, including the data processing equipment, the intellectual sensors, actuators, repeaters, central units in adaptive control strategies of aviation engine. The optimization method for processing information, using adaptive wavelet filters, as an optimal filter, that minimizes the average square of a common error for organizing the connection between wireless elements in the control systems of aviation gas turbine engine, has been considered, on the theoretical point of view. Also, the wavelets applications in the Wireless Distributed Automatic Control System (WDACS) for aviation engine, the requirements for the construction of its node, supported by the protocol stack, the scheme and the programs with a combination of connections the information exchange between elements have been considered, from the practical point of view.]]></description>
      <pubDate>Tue, 25 May 2021 16:20:02 GMT</pubDate>
      <guid>https://trid.trb.org/View/1849509</guid>
    </item>
    <item>
      <title>Performance Based Optimization of Intake and Injection Parameters of an Advanced Compressed Air Engine Kit</title>
      <link>https://trid.trb.org/View/1462621</link>
      <description><![CDATA[The increment in the application of fossil fuels is leading the world into a catastrophic state both environmentally and economically. Current demand for fuels exceeds its imminent supply and rather sooner than later energy demands will have to shift towards non-conventional fuels to cope with the situation. With constant developments in the automotive sector, several solutions have been found but none have been as good as gasoline to substitute it in the commercial market. One such solution being compressed air might solve this global fuel crisis, which serves a glowing advantage of being cheaper and greener as it produces zero tail-pipe emissions, and can help in decreasing automobile’s contribution to global warming. Though the potential energy stored in the compressed air limits its application to light duty vehicles and still there will be a need for other alternative solutions for the heavy duty vehicles in order to relieve the pressure from the fossil fuels. Post the development of an advanced compressed air engine kit for a 2-stroke air-cooled SI engine 145cc; there is a big scope for enhancing its performance and efficiency in order to commercialize this technology in production cars. Present investigation aims at optimizing the injector area, expansion ratio (final volume/initial volume) and weight of the flywheel in order to get maximum possible power output and torque from the engine. Valued statistics f\rom previous readings and analysis on aforementioned intake and injection parameters are deliberated and testing and performance analysis is conducted. The results help in obtaining optimum values of the intake and injection parameters and can be used to further enhance the performance of compressed air vehicles to produce a more efficient system.       ]]></description>
      <pubDate>Tue, 18 Feb 2020 10:20:36 GMT</pubDate>
      <guid>https://trid.trb.org/View/1462621</guid>
    </item>
    <item>
      <title>Strategy and Competitive Rivalry in the Original Equipment Manufacturer Single Aisle Market</title>
      <link>https://trid.trb.org/View/1491152</link>
      <description><![CDATA[The development of new jet aircraft has become the focal point of competition within the commercial aviation industry, pushing product development and positioning strategies to the core of the competitive game. This paper explores the competitive forces of the single aisle aircraft manufacturing market and how the rivalry between competitors affects their respective strategies. A survey was distributed to industry executives, along with interviews with key senior managers, to uncover and critique strategies the respective airframe original equipment manufacturers (OEMs) adopted. It was found that movements in the engine OEM industry were a key determinant in the competitive positioning of airframe OEMs during the period of this study ranging from 2004-2013. The focus OEMs established different strategies, considering the competitive actions of their rivals, to succeed in the single-aisle segment. Bombardier followed a niche strategy, differentiating itself in that niche by developing a clean sheet design aircraft. Airbus and Boeing use their competencies to create a broad cost and differentiation strategy, respectively. Embraer competes with its counterparts by adopting a niche strategy coupled with cost leadership in that niche.]]></description>
      <pubDate>Tue, 22 May 2018 17:22:33 GMT</pubDate>
      <guid>https://trid.trb.org/View/1491152</guid>
    </item>
    <item>
      <title>Application of Probabilistic and Nonprobabilistic Hybrid Reliability Analysis Based on Dynamic Substructural Extremum Response Surface Decoupling Method for a Blisk of the Aeroengine</title>
      <link>https://trid.trb.org/View/1464637</link>
      <description><![CDATA[For the nondeterministic factors of an aeroengine blisk, including both factors with sufficient and insufficient statistical data,based on the dynamic substructural method of determinate analysis, the extremum response surface method of probabilistic analysis, and the interval method of nonprobabilistic analysis, a methodology called the probabilistic and nonprobabilistic hybrid reliability analysis based on dynamic substructural extremum response surface decoupling method (P-NP-HRA-DS-ERSDM) is proposed. The model includes random variables and interval variables to determine the interval failure probability and the interval reliability index. The extremum response surface function and its flow chart of mixed reliability analysis are given. The interval analysis is embedded in the most likely failure point in the iterative process. The probabilistic analysis and nonprobabilistic analysis are investigated alternately. Tuned and mistuned blisks are studied in a complicated environment, and the results are compared with the Monte Carlo method (MCM) and the multilevel nested algorithm (MLNA) to verify that the hybrid model can better handle reliability problems concurrently containing random variables and interval variables; meanwhile, it manifests that the computational efficiency of this method is superior and more reasonable for analysing and designing a mistuned blisk. Therefore, this methodology has very important practical significance.]]></description>
      <pubDate>Fri, 28 Apr 2017 10:39:42 GMT</pubDate>
      <guid>https://trid.trb.org/View/1464637</guid>
    </item>
    <item>
      <title>Fan Casing Contouring Under Consideration of Aeroacoustics, Mechanics, Aeroelasticity, and Whole Engine Performance</title>
      <link>https://trid.trb.org/View/1456265</link>
      <description><![CDATA[Aircraft propulsion will continue to rely on gas turbine technology for the next decades to come. Thus, to achieve environmental agreements, ensure engine safety, and retain economic competitiveness, ongoing development with a multidisciplinary design approach is indispensable. In the present study, the multi-criteria analysis of the fan, a decisive component in modern aero engines, is examined. In particular, the interaction of the fan blades with the fan casing is analyzed and an appropriate design approach, including automatic optimization, is used. As one part of the disciplines conjunction, an automated aeroacoustic approach is realized. The aerodynamic and acoustic fitness functions and constraints are based on Reynolds-Averaged Navier–Stokes (RANS) simulations of the fan stage. PropNoise, a fast analytical prediction tool for fan noise, is used. It has been under development since recent years and is already validated on several test cases. Preliminary studies have shown that the flow in the rotor tip region is a major contributor to the broadband noise emission. Based on this, the optimization process focuses on the variation of the casing contour around the fan blades. The impact of the modified flow field in the rotor tip region concerning the aeroelastic behavior is also investigated. As aeroelastic evaluation requires a high level of know-how and is very time consuming, it is linked to the optimization process chain by a discrete evaluation of selected members. This allows a simultaneous adjustment of the design in case of aeroelastic issues. Furthermore, the impact of the fan modifications regarding the overall engine performance is evaluated. Off-design cycle calculations allow incorporating such detailed studies in a global engine optimization.]]></description>
      <pubDate>Mon, 27 Feb 2017 09:38:35 GMT</pubDate>
      <guid>https://trid.trb.org/View/1456265</guid>
    </item>
    <item>
      <title>Experimental Investigation and Design of a Shape-variable Compressor Cascade</title>
      <link>https://trid.trb.org/View/1456262</link>
      <description><![CDATA[The design of jet engine compressor blading always implies a compromise between design and off-design operation. The reason for this is a fixed blade geometry which has to be operated over a wide range of operating conditions. Consequently, maximum achievable efficiencies at design operation are limited by off-design requirements, e.g., a certain stall margin. This paper describes an approach using shape-variable blades equipped with integrated piezoceramic-based macro fiber composite (MFC) Actuators on the blade’s suction and pressure sides. By applying a voltage to these actuators, it is possible to increase and to decrease the blade stagger angle and therefore the blade turning. Compared to a conventional fixed blade profile, the actuated design is thus adaptable within a certain range regarding ambient conditions. The first part of the paper describes the geometry and structure of the shape-variable blades for use in a compressor cascade experiment. In the next part, the three-dimensional deformation behavior of all manufactured blades at different shape conditions is characterized with a photogrammetric measurement system called ATOS. The first results without aerodynamic loads show an average displacement at the trailing edge of approximately Δz ≈ 0.9 mm compared to the non-actuated condition. This corresponds to an average outlet angle variation of approximately ∆κ2 ≈ ± 1°. The third part of the paper presents the results of the low speed cascade experiment using a fully actuated cascade. On the one hand, the objective is to determine the influence of blade actuation on aerodynamic characteristics such as flow outlet angle, total pressure loss and pressure distributions. On the other hand, optical blade displacement measurements are used to investigate combined two-dimensional (2D) and three-dimensional (3D) deformation effects of blade actuation in conjunction with aerodynamic loads. For these measurements, the ATOS system is also used. The wake evaluations show that maximum blade actuation leads to flow outlet angle deviations up to ± 1° which can be described by an almost linear shift of the cascade performance without changing the loss distribution significantly. Furthermore, for the chosen profile this margin is approximately constant over the operating range.]]></description>
      <pubDate>Mon, 27 Feb 2017 09:38:15 GMT</pubDate>
      <guid>https://trid.trb.org/View/1456262</guid>
    </item>
    <item>
      <title>Online Fault-Tolerant Onboard Aeroengine Model Tuning Structure</title>
      <link>https://trid.trb.org/View/1440504</link>
      <description><![CDATA[Online onboard aeroengine models (OBEMs) have been widely used in health management, fault diagnostics, and fault-tolerant control. A mismatch between the OBEM and the actual engine may be caused by a variety of factors such as health degradation or sensor fault and may influence the effectiveness of the systems mentioned above. However, mismatch caused by unpredictable sensor fault is hardly distinguished from that caused by health degradation through the tuning process. A fault-tolerant OBEM tuning structure is provided to perform the online tuning function when health degradation and sensor fault coexist. This system includes three parts that include improved fault diagnostics and isolation (IFDI), a fault-tolerant OBEM tuning system (FTOTS), and a channel switching module. IFDI is used to distinguish the cause of mismatch and provide fault information, a FTOTS is used to complete an online tuning process based on information obtained from the IFDI, and the channel switching module is used to switch the working process from the IFDI to the FTOTS. Several simulation results show that this system is able to distinguish the causes of mismatch and complete online tuning in the case of sensor faults.]]></description>
      <pubDate>Wed, 21 Dec 2016 11:31:18 GMT</pubDate>
      <guid>https://trid.trb.org/View/1440504</guid>
    </item>
    <item>
      <title>Effect of temperature on the dynamic performance of C/C composite finger seal</title>
      <link>https://trid.trb.org/View/1422789</link>
      <description><![CDATA[The designs of sealing device have prominent influence on the performance of aero-engine. The high temperature environment during the working process of aero-engine also has important influence on the performance of sealing device which is located in the aero-engine. Finger seal has a flexible characteristic and high price performance compared with the other seal devices, thus it gets more attention, and lots of researchers have studied about finger seal’s performance recently. But so far the dynamic performance of finger seal considering temperature effect is not yet analyzed and discussed. Based on this, an equivalent dynamic model based on distributed mass considering temperature effect is proposed in the paper. The effects of environment temperature and heat through friction on the equivalent structural stiffness of finger stick and contact pressure between finger stick and rotor are discussed. Moreover, the data exchange between the dynamic and thermal analysis is confirmed based on the movement relationship between the rotor excitation and finger stick response. Therefore, the dynamic performance analysis of finger seal including thermal-structure coupling is obtained based on an equivalent dynamic method. The effect of temperature on the dynamic performance of finger seal using this model is analyzed, and the effect of C/C composite structural parameters on the finger seal performance is investigated considering the temperature effect. The above results show that the temperature effect has important influence on the performance of finger seal, so it is necessary to consider the temperature effect when the performance of finger seal is analyzed. The current work further improves the theoretical system about finger seal equivalent dynamic research, and has higher academic significance and engineering value.]]></description>
      <pubDate>Fri, 21 Oct 2016 16:36:32 GMT</pubDate>
      <guid>https://trid.trb.org/View/1422789</guid>
    </item>
    <item>
      <title>Aero Engine Component Fault Diagnosis Using Multi-Hidden-Layer Extreme Learning Machine with Optimized Structure</title>
      <link>https://trid.trb.org/View/1421243</link>
      <description><![CDATA[A new aero gas turbine engine gas path component fault diagnosis method based on multi-hidden-layer extreme learning machine with optimized structure (OM-ELM) was proposed. OM-ELM employs quantum-behaved particle swarm optimization to automatically obtain the optimal network structure according to both the root mean square error on training data set and the norm of output weights. The proposed method is applied to handwritten recognition data set and a gas turbine engine diagnostic application and is compared with basic ELM, multi-hidden-layer ELM, and two state-of-the-art deep learning algorithms: deep belief network and the stacked denoising autoencoder. Results show that, with optimized network structure, OM-ELM obtains better test accuracy in both applications and is more robust to sensor noise. Meanwhile it controls the model complexity and needs far less hidden nodes than multi-hidden-layer ELM, thus saving computer memory and making it more efficient to implement. All these advantages make our method an effective and reliable tool for engine component fault diagnosis tool.]]></description>
      <pubDate>Wed, 31 Aug 2016 08:14:58 GMT</pubDate>
      <guid>https://trid.trb.org/View/1421243</guid>
    </item>
    <item>
      <title>Aero Engine Fault Diagnosis Using an Optimized Extreme Learning Machine</title>
      <link>https://trid.trb.org/View/1399974</link>
      <description><![CDATA[A new extreme learning machine (ELM) optimized by quantum-behaved particle swarm optimization (QPSO) is developed in this paper. It uses QPSO to select optimal network parameters including the number of hidden layer neurons according to both the root mean square error on validation data set and the norm of output weights. The proposed Q-ELM was applied to real-world classification applications and a gas turbine fan engine diagnostic problem and was compared with two other optimized  (ELM) methods and original ELM, support vector machine (SVM), and BP method. Results show that the proposed Q-ELM is a more reliable and suitable method than conventional neural network and other ELM methods for the defect diagnosis of the gas turbine engine.]]></description>
      <pubDate>Fri, 01 Apr 2016 14:23:38 GMT</pubDate>
      <guid>https://trid.trb.org/View/1399974</guid>
    </item>
    <item>
      <title>Simplified compound suction schemes of an aspirated highly loaded compressor cascade</title>
      <link>https://trid.trb.org/View/1398955</link>
      <description><![CDATA[Active flow control should be adopted at more than one critical position in highly loaded aspirated compressors due to the severe flow separation and obvious three-dimensional characteristics of the flow field. A deep insight into the mechanism of the simplified compound boundary layer suction in a highly loaded compressor cascade was experimentally and numerically revealed in this paper. Locations of the two suction slots in the studied compound suction schemes were determined through previous experimental investigations on the single-slot suction schemes. Base on the one-side suction manner and the shared suction recycle system, the suction flow distribution over the suction surface slot (SS4) presented to be C-type along the spanwise both in single-slot cases and the compound suction schemes. On the other hand, the flow distribution over the endwall slot (EW1) was no longer that even along the axial direction after it cooperates with the SS4 slot, especially under the small total suction flow rate. The studied compound suction scheme owns obvious advantages in improving aerodynamic performance of the compressor cascade, when the total suction flow rate is big enough for both slots. About one-sixth loss reduction was achieved in the compound suction scheme with 1.5% suction flow rate. Therefore, the simplification of suction equipment via sharing one set of suction system and employing one-side suction manner is proved to be feasible and as effective in the studied multi-slot suction schemes.]]></description>
      <pubDate>Wed, 16 Mar 2016 09:36:43 GMT</pubDate>
      <guid>https://trid.trb.org/View/1398955</guid>
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